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Flat Fielding

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This function divides the image in Buffer A by a normalized version of the Image in Buffer B. The result is stored in Buffer C, which is displayed at completion of the function. 'Normalized' means each pixel value in Buffer B is divided by the average of all the pixel values in image B.

Typical Flat Field Image
Typical Flat Field
The main use of this function is to calibrate the image in Buffer A by using a 'flat field' image in Buffer B. A 'flat field' image is an image of a uniformly lit field which essentially contains information about pixel sensitivity, vignetting, dust on the optics, etc. By normalizing the flat field before the division, the resulting range of pixel values is very close to the original. JIMSAIP uses extended precision mathematics to carry out the operations before saving the pixel values as integers.